Refrigerating apparatus



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REFRIGERATING APPARATUS Original Filed Jan. 31, 1935 s Sheets-Sheet 1 as I g I NV NTOR.

Feb. 10, 1942.

BY v M 2 2 Patented Feb. 10, 1942 REFBIGERATING APPARATUS Harry B. Hull, Dayton, Ohio, assignorto General Motors Corporation, Dayton, Ohio, a corporation of Delaware Original application January 31, 1935, Serial No.

Divided and this application December I 18, 1937, Serial N0. 180;629

1 Claim.

This invention relates to refrigeration and more particularly to the conditioning of air for railway cars and the like.

This application is a division of my copending application Serial No. 4,344 filed January 31, 1935, now Patent No. 2,104,386.

It is an object of this invention toprovide an air conditioning system for railway cars or the like in which the compressor may be driven at varying speeds and yet furnish satisfactory-refrigeration for the car.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings: 7

Fig.1 is a diagrammatic representation of the driveand refrigerating system on the car;

Fig. 2 is a view in cross-section of a compressor gihich may be used in the system shown in r Fig. 3 is a cross-section of the compressor taken along the lines 3-3 of Fig. 2; and

Fig. 4 is a cross-section similar to Fig. 3, but

showing the centrifugal weights in their extended position.

The car to be refrigerated may be provided with the usual body II which carries a wheel, truck Ii which in turn carries one or more wheel' axles i2. The truck ii is free to turn with respect to the body ll. The body III also carries a compartmentthe air for which is to be conditioned.

A suitable drive is provided between the car axle i2 and a motor-generator I3, which is carried on the body i0, such that the motor-generator is driven in the same direction regardless of the direction of travel of the car. The rate of rotation of the generator may be varied in accordance with the'speed of the car. To this it. The shaft 22 is connected by a clutch 23 with the shaft 24 of thecompressor whichis also carried on the body it. The arrangement is such that the motor-generator it drives, as a motor, the compressor 24 when the car is standing still or when it is runningbelow a generating speed. This is accomplished because the gear box i8 is provided with an over-running clutch which permits the motor to run without driving the car. when the car reaches a gen-- erating speed, the motor-generator charges a battery and the clutch 23 is actuated in ace end, suitable belt drives :4. is, is and u may be interposed between the shaft i2 and the gear box It such that the shaft I! has imparted to it rotation in the same direction regardless of the rotation of the shaft l2. Any suitable construction of gears may be used in gear box it,

and merely as an example, reference is made to the copending application of Harry B. Hull and D. F. Alexander, Serial No. 4,345, filed January 31, 1935, now Patent No. 2,104,387. The shaft i9 is-placed in axial sliding keyways such that it can enter or recede from the box it. The shaft '19 is connected by means of universal Joints 20 cordance with temperature conditions created by the apparatus to start and stopthe compressor 25. The axle therefore drives the generator to charge the battery, and drives the compressor under control of a thermostat or the like. 7

The compressor 25 is of the character which automatically varies its volumetric capacity with changes in speed of rotation. Any type of compressor capable of accomplishing thismay be used.

The compressor delivers compressed refrigerant to a condenser 26 which discharges into the liquid refrigerant receiver 21 and from whence refrigerant flows through the solenoid valve 28 and automatic expansion valve 29 to evaporator 30 and from which the refrigerant return through the line 3i to the compressor 25. The valve 28 may be of the character which automatically introduces refrigerant into the evaporator 30 when'the pressure therein is lowered to a predetermined limit, but this action'is modified by a thermostatic bulb 32 which automatically throttles the valve 28 when a sufflcient refrigerating effect reaches the bulb .32. The operation of the refrigerating system is controlled by a thermostat it, placed in the compartment to be cooled, in a manner hereinafter more fully described. Air is forced over the evaporator 30 by a'fan 34 driven by a motor 25, the air which ric capacityin accordance with a change of speed is shown in Figs. 2, 3 and 4. In this compressor, a cylindrical casing 50 is provided with an' intake 5| which is connected to-the pipe M. The spaces ,52 in the casing 50 are on the compression side I of the system and are interconnected by passageways 53 and 53a so that the compressed refrigerant from all of the compressing cylinders may be discharged through the opening 54 to the condenser 26 and so that the lubricant may equalize; and 2i with the shaft 22 of the motor-generator to throughout the casing 50. The pistons 55, it and v VI of centrifugal weights 1 to bring the Pistons I6 or IT into I! are gyrated by the rotation of shaft 24 so that refrigerant is taken into the compression chambers 60a through the branches it, and the compressed refrigerant is discharged past the check valves It intothe spaces 52. The casing 84 is provided with a plurality of pumping cylinders 64 which are secured within casing II in any suitable manner, as by bolts 8|, a plurality of these bolts being used around the circumference. The shaft 24 is provided with a plurality of eccentries 62, 6t and 64 and the arrangement is such that pistons 56 and II are automatically rendered inactive as the speed of the shaft 24 increases. Any suitable centrifugal arrangement may be used for this purpose. Thus a plurality ll are swingingly moimted to the rings 68 secured to the shaft 24. the fulcrum thereof being indicated at I1. Buitable springs 68 hold the centrifugal weights "in a retracted position (as shown in Fig.3) until the speed exceeds the pulling power of the springs when the weights fly outward as indicated in Fig. 4. The weights 65 are provided with slots 69 which cooperate with pins II carried by arms ll of eccentric sleeves 12. The arrangement is such that the combined maximum eccentricity of the eccentrics 63 or 04 and i2 is just sufficient pumping engagement with the cylinders 60. When the eccentrics 63 or 84 and I! are thrown out of alignment to each other by the outward movement of the weights 5, then the engaging contact between the piston and the cylinder is broken as indicated in Fig. 4. The springs on' the weights which govern piston It stronger than those on the weights of piston 81. Thus when a certain speed is attained piston 81 is made inoperative. Then if the speed increases to another predetermined spe ed,piston ll becomes inoperative and thereafter onepiston ll furnishes refrigeration during the highest speeds of the car. The number of pistons shown is; merely illustrative of the invention, however, and any number may beused; as desired.

Any suitable amusement of piston may be used. In the particular embodiment shown the pistons are annular in cross-section and are held in place by plates Ila and Ho which are bolted to the cylinders I by means of bolts 12a distributed around the circumferences of plates II are made somewhat 1 Jill and ii. An opening 13 is made in the plate H which provides an outlet for the compressed gases, the opening ll being closed by the check valve 50. A suitable divider plug 14, urged against the piston 56 by the spring 15, is provided to divide the compression and suction sides of the chamber. Any suitable type of seal, indicated at II, may be provided to prevent the escape of gases along the shaft 24 where it emerges from the casing 54.

A suitable lubricant pump 24a may be mounted on the shaft 24 and may have its intake 24b connected with the lubricant 240. The discharge 24c connects with an axial bore 24] which distributes lubricant to the bearings and to the oil sump of seal 10 and other parts of the compressor.

Any suitable electrical connection between the battery, the motor-generator, the thermostat and the solenoid valve may be provided. For a description of one circuit arrangement which may be used reference is hereby made to my patent No. 2,104,386, referred to hereinabove.

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claim which follows.

What is claimed is as follows:

In a multiple cylinder compressor, a main housing, a drive shaft within said housing, and a plurality of rotary compressor units driven thereby each of which units comprises means forming a pumping cylinder having a cylindrical wall, inlet and outlet ports for said cylinder, a

divider block between said ports, a cylindrical piston of less diameter than said cylinders, means for positioning said piston in varying eccentric relation within said cylinder, means including said drive shaft on which said whereby the axis of said piston is caused to revolve about a center within the cylindrical wall of said cylinder. and speed responsive means for moving said piston into varying eccentric relation with said cylindrical wall in accordance with the speed of said shaft, one of said speed responsive means being responsive to a different speed than another of said speed responsive means.

HARRY B. HULL.

piston is mounted 

